1. 8233. The angle of incidence is that acute angle formed by A. the angular difference between the setting of the main airfoil and the auxiliary airfoil (horizontal stabilizer) in reference to the longitudinal axis of the aircraft. B. a line parallel to the wing chord and a line parallel to the longitudinal axis of the aircraft. C. a line parallel to the wing from root to tip and a line parallel to the lateral axis of the aircraft.